title: Congenital cutaneous histiocytosis in a piglet.
abstract: A 2-week-old crossbred male piglet with numerous congenital, variably sized macules, plaques, and papules distributed all over the body was submitted for necropsy. Significant gross and histological lesions were restricted to the skin. On light microscopic examination, these cutaneous lesions corresponded to dermal and/or subcutaneous masses composed of spindle-shaped to round cells that multifocally contained hemosiderin; epidermotropism was not observed. Immunohistochemically, the neoplastic cells were strongly positive for CD204; moderately positive for CD163, lysozyme, and vimentin; and negative for Mac 387, α-1-antitrypsin, S-100 protein and E-cadherin; frozen tissues were not available for CD1a and CD11c. Transmission electron microscopic examination of sections from formalin-fixed tissues did not reveal Birbeck's granules. The clinical, morphological, and immunohistochemical results were consistent with a congenital cutaneous histiocytosis of non-Langerhans cell origin. The condition most resembled juvenile xanthogranuloma in humans, a generally skin-limited non-Langerhans histiocytic disorder that can be congenital. Cutaneous and/or systemic histiocytic disorders are well characterized in dogs and have been described in cats, and a case with some similarities to ours has been reported in a neonatal piglet, but this is to our knowledge the first immunohistochemically supported report of histiocytosis in the pig and congenital histiocytosis in animals.
authors.affiliation: Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, Quebec, Canada pierre.helie@umontreal.ca.
authors.forename: P
authors.initials: P
authors.lastname: Hélie
authors.affiliation: Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, and Diagnostic Center for Population and Animal Health (DCPAH), Michigan State University, East Lansing, MI, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kiupel
authors.affiliation: Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Drolet
mesh_terms: D000818:Animals; D017809:Fatal Outcome; D015616:Histiocytosis, Non-Langerhans-Cell / Q000151:congenital / Q000473:pathology / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D012871:Skin Diseases / Q000151:congenital / Q000473:pathology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000151:congenital* / Q000473:pathology*
keywords: Sus scrofa; histiocytosis; immunohistochemistry; pathology; skin